1. Field of the Invention
The present invention relates to an exercise wheel that has a longer travel, prevents backward displacement, and increases longevity of torsion springs. The present invention also relates to an exercise wheel that can be operated with less force and adjusted according to user's demand.
2. Description of the Related Art
FIGS. 6 and 7 of the drawings illustrates a conventional exercise wheel that includes a housing 1', two grip rods 2', a main gear 3', two roller pairs 4', and two torsion springs 5'. The housing 1' includes a compartment with a downwardly facing opening and aligned holes 11' on two sides thereof into which the grip rods 2' are mounted. Two stop rods 12' are mounted inside the housing 1'. The main gear 3' is mounted to the grip rods 2' and includes a peg 32' on each side thereof. Each roller pair 4' includes two rollers 41' connected by a shaft 42' that has teeth 421' formed on an outer periphery thereof for meshing with teeth 31' of the main gear 3'. Each torsion spring 5' includes two ends 52' and 53' that are attached to an associated peg 32' and an associated stop rod 12', respectively.
When in use, the user bends downward and grasps the grip rods 2' to make roller pairs 4' roll on the ground. During rolling of the roller pairs 4', the torsion springs 5' are tensioned by the main gear 3' via transmission of the teeth 421' and 31'. When the main gear 3' is turned for one turn the end 52' of the torsion spring 51' bears against the stop rod 12', and the main gear 3' and the roller pairs 4' are thus stopped. Thus, maximal travel of the exercise wheel is limited. The torsion springs 51' may return the exercise wheel to its initial position.
Nevertheless, it is found that the maximum travel for the exercise wheel corresponds to one turn of the main gear 3', which might be insufficient for the user whereby a larger gear is required for a longer travel. In addition, the torsion springs 5' might be damaged or even broken if the torsional travel is too large for the torsion springs 5'. As a result, the ends 52' and 53' of the torsion springs 5' might disengage from the stop rods 12' and the pegs 32' and thus cause injury to the user. Further, the roller pairs 4' are aligned one with the other such that the exercise wheel can be moved rectilinearly only.